Spectroscopy

Low-temperature optical probe-station

This set-up consists of a cryogenic probe station integrated with a confocal optical microscope. It allows electro-optical testing of light-emitting diodes or optical detectors with 2 μm spatial resolution and 20 GHz electrical bandwidth at 4K.

 

Low-temperature photoluminescence characterization

Our general photoluminescence facility provides detection between 500 and 1600 nm with multichannel detectors and up to 3.5 µm with a single channel InSb detector. It also allows the luminescence mapping of as-grown wafers with a sub-micron resolution.

 

Scanning Near-field & Optical Microscope

Room temperature Scanning Near Field Optical Microscope equipped with: InGaAs APD, special probes for simultaneous far-field optical access or nanoscale fluid delivery, nanopositioned lensed fibers system for coupling with on-sample waveguides.

 

Femto-second Pump-Probe Spectroscopy

Two-wavelength pump-probe spectroscopy with a timing jitter below 100 fs, either using two synchronized Ti:sapphire lasers or the combination of a Ti:sapphire laser and an Optical Parametric Oscillator (OPO) tunable between 1030 and 1300 nm and 1350-1600 nm. Presently, the setup is mainly used for time-resolved differential reflectivity (sensitivity ΔR/R<5x10-7).

Single Dot Spectroscopy

Our microphotoluminescence facilities allow single dot spectroscopy for both GaAs and InP based nanostructures with a spatial resolution down to 400 nm. The set-up allows resolving linewidths down to 20 microeV for an individual emitter.

 

Single Photon Spectroscopy

The nonclassical statistics of light emitted by self-assembled quantum dots is studied in two photon-correlation experiments, for wavelengths below and above 1000 nm, with temporal resolution down to 40 ps.

 

Single-Spins MagnetoOptics

 To address single spins in semiconductor nanostructures, we study the luminescence in magnetic fields with our low-temperature confocal microscope. The high spatial resolution of 300 nm is combined with the high spectral resolution (10 μeV). The lowest achievable temperature is currently 300 mK.